Mixture control



F. BARFOD MIXTURE CONTROL April 4, 1961 3 Sheets-Sheet 1 Filed June 24, 1959 FREDE R! K BARFOD.

INVENTOR.

ATTORNEY.

April 4, 1961 F. BARFOD I 2,977,949

MIXTURE CONTROL Filed June 24, 1959 3 Sheets-Sheet 2 FUEL.

I I l lNDUCT/ON PASSAGE PRE$$URE INVENTOR.

FREDERIK BARFOD.

jawxw ATTORNEY.

F. BARFOD MIXTURE CONTROL April 4, 1961 3 Sheets-Sheet 5 Filed June 24, 1959 FREDERIK BARFOD INVENTOR.

BY I

ATTORNEY,

'CONTROLZ.

Frederik Barfod," Detroit, Mich. ,,=ussiguor to. The Bendix. Corppration,.a:corpol'atiomofDelawarev i Filed June- 24,? mesa. No: 822,587 3Claims. (Cl.123---140) The present invention relates generally to a mixture control for :an internal combustiorr engine fuel supply system and more particularly to mixture control for regulating the fuel supply to an engine as a function of atmospheric pressure and induction passage pressure.

It is an object of the present invention to provide in a mixture control power enrichment means which is simple in construction and reliable and accurate in operation.

It is another object of the present invention to provide in a mixture control integrated atmospheric pressure and induction passage pressure responsive controls wherein the atmosphericpressure control is effective throughout the operating range of the mixture control to modulate fuel flow with changes in atmospheric'pressure.

'I'hese and other objectsof the invention will become .readily apparent from the following description taken in connection with the accompanying drawings'wherein:

Figure l is a sectional view of a mixture control cmbodying the present invention;

Figure 2 is a graph of the operation of the control shown in Figure 1; and

Figures 3 and 4 are partial views of Figure 1 showing the rearrangement of parts under different operating conditions.

Referring now to the drawings, numeral designates a fuel injection device which may be of the type shown in my copending application Serial No. 604,483, filed.

August. 16, 1956. A lever 12 is connected to the fuel injection device 10 for varyingthe quantity of fuel to the engine 14. v

The mixture control is designated generally by the numeral 16 and includes a housing 18 which is bolted to the fuel injection device" 10 by suitable bolts 20. Housing 18 is provided with a cylindrical bore 22 in which is reciprocably mounted a hollow cylinder 24. ,Cylinder 24 is closed at end 26 and open at its opposite'end '28;

. A cup-shaped piston 30 is reciprocably disposed in cylinder 24 and is connected to leve'rj12 by a rod 32. Piston 30 is urged toward its lower extremal position by first and second springs designated respectively 34 and 36 disposed in cylinder 24.- The first spring'34 reacts agaiiist a spring retainer 38 and the-end wall of piston 30. The

stream or. posterior to throttle valve 50. f I A bellows 52- is secured to housing 18. adjacent' cylinder 24'by means of-stud 54 andnutj 56, Bellows 52 m'ay be evacuated so as to be responsive to ambient or atmospheric: pressure and insensitive to temperature; or 4' it'may b'e" filledwith an inertlgas such as iiitrogen-whcre by the bellows will befrendered responsivefto' both am- ,bient airpressure and ambientair temperature.;" e cts' from one fendof be'lloitrisj,52 and.

mixture lever-5.62. to. the stud; Lever .62" is connectedat its other endstoan. adjustable pivotvor. fulcrum 64 thy an intermediate lever. 66 which'is-pivoted .at its ends to lever 62.and..fulcrum .64- by pins 68and 70 respectively. Lever 6,2 is. pivotally connected intermediate its endslto a bifureatedtmember 72. which. proje'ctsfriom. the. closed end' 26- of 7 cylinder 24. Expansion. or contraction. ofmbellows 52.in response tochanges inatmospheric pressureis transmitted, through lever 62. tocause cylinder 24 to recipr o@ cate in, bore. 22. Figure. 1. represents the p ositionuof 12am: at. sea 1eveli.with the, induction passage pressure equal 'to atmospheric pressure. Figure 4 showswthe posi-..

tion .in atmospheric pressure. When theinductionpan. sage pressure :is 1 reduced a. predetermined. amount: below: atmospheric pressure, piston 30 will be moved upwardly. in opposition to spring 34 to bring spring retainer 38 into engagement with piston 30 such as is shown in Figure 3.

When spring retainer 38 is in engagement with'piston 30 will be'moved to an upper extremal position. In the upper extremal position of piston 30 spring 34 is in its ineffective position and spring '36 is partly compressed. As the throttle 50 is moved toward open position increasing the induction passage pressure piston 30 will move downwardly. Spring 34 is calibrated such that when the induction passage pressure reaches a predetermined value that the force of spring 34 will exceed the pressure difierential action on piston 30 and cause the piston to be moved downwardly. The effect of spring 34 is shown graphically in Figure 2 wherein the curve A-B represents the modulation of fuel by the mixture control when only spring 36 is effective. The curve B-,-C represents the effect of spring 34 at higher induction passage pres- 1 sures. At'the predeterminedinduction passage pressure designated. B in Figure 2, spring 34 commences to be effective and markedly increases the fuel supply to the engine with increase in induction vide a. power enrichment mixture.

Iclairn: i

1. A. control for a fuel supply device comprising a bellows'responsive to ambient air pressure, a lever fulcrumed at one endand pivotally secured to said bellows at its other end, a cylinder having a closed and an opened end, means pivotally' securing said cylindertosaid lever ,intermediate'the ends of said lever, a piston reciprocably disposed in said cylinder, means operatively connecting 1 said piston to said device for'controlling the fuel supplied thereby, aspring retainer in said cylinder, a pair of springs in said cylinder reacting respectively against the closed end of said cylinderfand said retainerand against said retainer and said piston, and means'for con necting the interior of said cylindertintermediate the closed end thereof and said piston with a source of pressure lower than atmospheric pressure, said piston being I moved into engagement with said retainer when the pressure in "said cylinder reaches a {predetermined value. Amixtur'e control arena injecticndevice adapted Patented Apr. 4, 1961 passage pressure to proto supply fuel to an internal combustion engine having an induction passage comprising a housing, a cylinder reciprocably mounted in. said housing, a bellows respon-r sive to ambient air pressure mounted on said housing,

a lever fulcrumed at one end and connected to 'saidbellows and cylinder respectively at its other end and intermediate its ends, means adapted to connect :the interior of said cylinder. to said induction passage, a piston in said cylinder responsive to changes in induction passage pressure,.a spring retainer in said cylinder,

a first spring in said cylinder reacting between said re-' tainer and said piston, said piston being movable; into engagement with said retainer at .a predetermined induction passage pressure, a second spring in said cylinderr'eacting between a portion of said cylinder and said retainer adapted to oppose further movement of said piston after said piston engagessaid retainer, and means adapted to connect said piston to said fuel injection device.

3. A mixture control for a fuel injection device adapted to supply fuel to an internal combustion engine having an induction passage comprising a bellows responsive to ambient air pressure, a cylinder closed at one end, means connecting said cylinder to said bellows for axially moving said cylinder as a function of bellows movement, means connecting the interior of said cylinder to References Cited in the file of this patent UNITED STATES PATENTS 2,134,658 Charley Aug. 25, 1938 

